The Powley computer is a "slide rule" type device which is designed to
allow you to pick the best IMR series powder for your rifle cartridge when
certain parameters about the cartridge are known.
     The original Powley computer was designed by Homer Powley some years ago
before the advent of the microcomputer.  It's slide rule form makes it somewhat
slow to use and somewhat error prone.  The purpose of POWVERxx.BAS is to
eliminate the errors and to speed up the operation.  With the original Powley
computer, it could take almost 15 minutes to set up the calculations and
recheck what you had done.  Using a microcomputer, you could do at least 10
calculations for different cartridges AND get a ballistics print out too.
     POWVERxx.BAS was originally written by me in 1980.  The first ballistics
calculations were, at best, "close".  I am not sure of the time frame, but Mr
Davis of the American Rifleman staff published a program for the TRS80 which
did a VERY nice job of calculating exterior ballistics.  I modified his program
and combined it with my own POWLEY program.  The program has been in a
continual state of "update" ever since.
     The current version 2.2 (POWVER22.BAS) is designed to run on the IBM PC
or it's clones.  Actually, the code is plain vanilla Microsoft Basic, and
should be easy to modify to just about any machine.  By the time this file is
read, the current version is hard to tell - I am always correcting, compressing
and generally updating this program.  What ever the version number, it should
run error free and with valid results!
     What kind of accuracy should you expect between the theory and the
practice?  To a large extent that will depend on your measurement of the
various parameters needed by the program.  In general, assuming you do your
part reasonably well, 5% should be expected in the Powley portion of the
program, and 1 to 2% in the ballistics tables when compared to published
information in the various reloading manuals.

     Before continuing, it should be made clear:

               THE RESULTS OF THIS PROGRAM ARE THEORETICAL

               DO NOT USE THESE LOADS WITHOUT CHECKING A

                        RELOADING MANUAL!


     Read and heed the above warning!  It's not just there to cover my butt!


     Values you will need to know for the program:

     Bore diameter:  Nominal bore diameter will do.
     Case Capacity:  The amount of water the case will hold when the bullet
                     you are using is seated to the depth you want.  There are
                     various ways of measuring this, and a planned Version will
                     allow you to just name the cartridge and the computer will
                     "look it up".  "Pet Loads" by Ken Waters lists case
                     capacity in most of the articles.
     Barrel Length:  This is the distance from the muzzle to the base of the
                     seated bullet.  Most reloading manuals suggest ways of
                     determining this distance.
     Ballistic Coef: You can find this in the reloading manual published by the
                     bullets maker.